High definition and low power partial functionality communication link

ABSTRACT

Communication link including a cable containing four pairs of wires, three transmitters to transmit uncompressed video data and audio data over three of the pairs of wires to three receivers, and two transceivers to form a bidirectional multi data type communication link over the fourth pair of wires. An active mode of operation for transmitting the uncompressed video data and the audio data over the three pairs of wires, and for transmitting bidirectional data over the fourth pair of wires. And a first low power partial functionality mode of operation for transmitting bidirectional system controls.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation-in-part of application Ser. No.11/703,080, filed on Feb. 7, 2007, incorporated herein by reference.This application also claims the benefit of U.S. Provisional PatentApplication No. 61/056,410, filed on May 27, 2008, incorporated hereinby reference. This application also claims the benefit of U.S.Provisional Patent Application No. 61/086,174, filed on Aug. 5, 2008,incorporated herein by reference

BACKGROUND

A multimedia system transmitting, for example, video, audio, andcontrols may enter a standby mode, enabling limited performance, inorder to reduced power consumption. In some cases, limited performancerefers to transmitting only a subset of the data types that aretransmitted in the non-standby mode. For example, a multimedia source instandby mode may still transmit and receive system control data thatenable it to read the properties of a sink device, that is also instandby mode, to which it is connected. In other words, there is no needto turn on the source and/or sink devices in order to read theirproperties.

Current video, audio, or multimedia solutions transmit some or all oftheir standby and/or low power data types over dedicated wires. Forexample, a High-Definition Multimedia Interface (HDMI™) includesdedicated wires for DDC, HPD, and CEC controls. DisplayPort™ includestwo wires for transmitting the auxiliary data. The above solutionsimplement the standby mode by turning off the transceiver(s) that arenot required for transmitting the data types that are supported by thestandby mode. For example, in HDMI, only the transceivers that arephysically connected to the wires used for transmitting the standby modedata types are operated in standby mode. In other words, standard HDMIsystems include dedicated control wires that are connected to dedicatedmodems, and only these modems operate in standby mode. Moreover, thestandby mode bandwidth is much smaller than the regular bandwidth, andallocating dedicated wires for the standby mode increases the totalnumber of required wires because the standby wires are not used forsignificantly increasing the bandwidth of the regular mode of operation.

BRIEF SUMMARY

In one embodiment, a communication link including: a cable containingfour pairs of wires, three transmitters operative to transmituncompressed video data and data over three of the pairs of wires tothree receivers, and two transceivers operative to form a bidirectionalmulti data type communication link over the fourth pair of wires; anactive mode of operation for transmitting the uncompressed video dataover the three pairs of wires, and for transmitting bidirectional systemcontrol data, bidirectional general data, and audio data over the fourthpair of wires; and an LPPF mode of operation for transmitting over thefourth pair of wires a subset of the data types transmitted in theactive mode of operation over the fourth pair of wires.

In one embodiment, a communication link including: a cable containingfour pairs of wires, three transmitters operative to transmituncompressed video data and audio data over three of the pairs of wiresto three receivers, and two transceivers operative to form abidirectional multi data type communication link over the fourth pair ofwires; an active mode of operation for transmitting the uncompressedvideo data and the audio data over the three pairs of wires, and fortransmitting bidirectional data over the fourth pair of wires; and afirst LPPF mode of operation for transmitting bidirectional systemcontrols.

In one embodiment, a communication device including: a cable containingwires, at least one transmitter operative to transmit uncompressed videodata over a first subset of the wires, and a transceiver operative totransmit bidirectional data including at least two data types over asecond subset of the wires; an active mode of operation for transmittingthe uncompressed video data over the first subset of the wires, and fortransmitting bidirectional data over the second subset of the wires; andan LPPF mode of operation for transmitting over a third subset of thewires a subset of the data types transmitted in the active mode ofoperation over the second subset of the wires.

Implementations of the disclosed embodiments involve performing orcompleting selected tasks or steps manually, semi-automatically, fullyautomatically, and/or a combination thereof. Moreover, depending uponactual instrumentation and/or equipment used for implementing thedisclosed embodiments, several embodiments could be achieved byhardware, by software, by firmware, or a combination thereof. Inparticular, with hardware, embodiments of the invention could exist byvariations in the physical structure. Additionally, or alternatively,with software, selected functions of the invention could be performed bya data processor, such as a computing platform, executing a softwareinstructions or protocols using any suitable computer operating system.

BRIEF DESCRIPTION OF THE DRAWINGS

The embodiments of the present invention are herein described, by way ofexample only, with reference to the accompanying drawings. No attempt ismade to show structural details of the embodiments in more detail thanis necessary for a fundamental understanding of the embodiments. In thedrawings:

FIGS. 1A-1B are schematic diagrams of one embodiment of the invention;

FIGS. 2A-2B are state machines of embodiments of the invention;

FIG. 2C is a schematic diagram of one embodiment of the invention;

FIGS. 3-4 illustrate data types in accordance with one embodiment of theinvention;

FIG. 5A illustrates a MDTCL in accordance with one embodiment of theinvention;

FIG. 5B illustrates a multi stream daisy chain in accordance with oneembodiment of the invention;

FIG. 6 illustrates a receiving path in accordance with one embodiment ofthe invention;

FIG. 7 illustrates a transmitting path in accordance with one embodimentof the invention;

FIG. 8 is a schematic diagram of one embodiment of the invention;

FIG. 9 illustrates a sink side of a MDTCL in accordance with oneembodiment of the invention;

FIG. 10 illustrates a source side of a MDTCL in accordance with oneembodiment of the invention;

FIG. 11 illustrates a multimedia system in accordance with oneembodiment of the invention;

FIG. 12 illustrates one embodiment of a state machine of a MDTCL inaccordance with one embodiment of the invention;

FIG. 13 illustrates a communication device in accordance with oneembodiment of the invention;

FIG. 14 illustrates a communication device in accordance with oneembodiment of the invention;

FIG. 15 illustrates a communication device in accordance with oneembodiment of the invention;

FIG. 16 is a flow diagram of a modulation based method in accordancewith one embodiment of the invention;

FIG. 17 is a flow diagram of a symbol rate based method in accordancewith one embodiment of the invention;

FIG. 18 is a flow diagram of a throughput based method in accordancewith one embodiment of the invention;

FIG. 19 is a flow diagram of a link type based method in accordance withone embodiment of the invention; and

FIG. 20 is a flow diagram of a functionality negotiation based method inaccordance with one embodiment of the invention.

DETAILED DESCRIPTION

In the following description, numerous specific details are set forth.However, the embodiments of the invention may be practiced without thesespecific details. In other instances, well-known hardware, software,materials, structures and techniques have not been shown in detail inorder not to obscure the understanding of this description. In thisdescription, references to “one embodiment” or “an embodiment” mean thatthe feature being referred to is included in at least one embodiment ofthe invention. Moreover, separate references to “one embodiment” in thisdescription do not necessarily refer to the same embodiment. Illustratedembodiments are not mutually exclusive, unless so stated and except aswill be readily apparent to those of ordinary skill in the art. Thus,the invention may include any variety of combinations and/orintegrations of the embodiments described herein. Also herein, flowdiagrams illustrate non-limiting embodiment examples of the methods, andblock diagrams illustrate non-limiting embodiment examples of thedevices. Some flow diagrams operations are described with reference tothe embodiments illustrated by the block diagrams. However, the methodsof the flow diagrams could be performed by embodiments of the inventionother than those discussed with reference to the block diagrams, andembodiments discussed with reference to the block diagrams could performoperations different from those discussed with reference to the flowdiagrams. Moreover, although the flow diagrams may depict serialoperations, certain embodiments could perform certain operations inparallel and/or in different orders from those depicted. Moreover, theuse of repeated reference numerals and/or letters in the text and/ordrawings is for the purpose of simplicity and clarity and does not initself dictate a relationship between the various embodiments and/orconfigurations discussed.

The term “different data types” or “data types” or “types of data” asused herein denotes symbols that are used for different purposes and/orfeature different characteristics. Examples of different data typesinclude, but are not limited to: video pixel data; audio data; videosynchronization control data, such as horizontal and vertical videopicture synchronizations; video system controls, such as CEC, HPD andDDC signals; or general data transmissions, such as Ethernet data, USBdata, or RS232 data; or infra-red (IR) control data. The data types mayalso be differentiated by features such as time sensitivitycharacteristics of the data, the required quality of transmissionassociated with the data, or the required throughput for each type ofdata. Examples of such data types include, but are not limited to: (i)time sensitive data, such as video pixel data or audio data, and timeinsensitive data, such as Ethernet data and video system controls; or(ii) data requiring high transmission quality, such as videosynchronization controls or video system controls, and data requiringrelatively low transmission quality, such as video pixel data.

The term “multi data type communication link” (MDTCL) as used hereindenotes a communication link that transfers at least two different datatypes. The different data types may be multiplexed into one or more datastreams that are transmitted over the MDTCL by the same one or moremodems. In the embodiments of the present invention, a MDTCL comprisesat least one active mode of operation and at least one low-powerpartial-functionality (LPPF) mode of operation. While in the LPPF modeof operation, the MDTCL: (i) consumes less power than the power consumedin the active mode of operation, (ii) transmits at a lower throughputthan the throughput transmitted in the active mode of operation, (iii)transfers only a subset of the data types that are transferred in theactive mode of operation, and (iv) optionally transfers one or more lowbandwidth data types that are not transferred in the active mode ofoperation. It is to be understood that the communication channel is notturned off while operating in the LPPF mode of operation. For example,assuming the LPPF mode of operation is utilized for transmitting systemcontrol data, there should be no need to establish the communicationchannel each time a system control datum is to be transmitted. It isalso to be understood that the LPPF is a mode of operation and thereforeit may transmit data repetitively without changing the mode ofoperation. In one embodiment, the LPPF mode of operation is nonisochronous and non mesochronous.

The term “high definition” as used herein denotes at least 720p, 1080iwith a total bitrate of more than 1 Gbit per second; wherein the totalbitrate equals to the number of lines times the number of columns timesthe refresh rate times the number of bits per pixel.

FIG. 3 illustrates different data types as a function of the requiredtransmission quality and the required bandwidth. As illustrated, videopixel data requires high bandwidth and low transmission quality; generaldata, audio data, video synchronization control data, and video systemcontrol data all require lower bandwidth and require higher transmissionquality in increasing order. FIG. 4 illustrates different data types asa function of the required transmission quality and the required timesensitivity. As illustrated, video pixel data, audio data, and videosynchronization control data all require strict timing and requiretransmission quality in increasing order; general data, such asEthernet, RS232 data, or USB data, and video system control data areboth less time sensitive and require transmission quality in increasingorder. It is to be understood that FIGS. 3 and 4 are just schematicillustrations and should not limit the scope of the disclosedembodiments.

In one embodiment, a communication link having at least two modes ofoperation, operating over the same physical media, connects between asink device and a source device. As a non limiting example, the sinkdevice may be a display device and the source device may be an HDMIsource or an Ethernet source. The link identifies the source andoperates according to the type of the source.

FIG. 1A illustrates one embodiment of a MDTCL having two modes ofoperation. The MDTCL has two transceivers (12 a, 12 b). A first mode ofoperation 13, referred to as the active mode, transmits relatively lowthroughput bidirectional control signals 17 and relatively highthroughput unidirectional data signals 18, over the four conductivewires (11 a, 11 b 11 c, 11 d) of the cable 11. A second mode ofoperation 14, referred to as the low-power partial-functionality (LPPF)mode, transmits relatively low throughput bidirectional control signals16, over a subset (11 c, 11 d) of the conductive wires of the cable 11.The selector 15 illustrates that the required mode of operation may beset as needed. In one example, the bidirectional control signals 17 aremulti media controls and/or HDMI controls; the unidirectional datasignals 18 are uncompressed high definition digital video signals; andthe bidirectional control signals 16 are standby signals.

Optionally, in the active mode of operation 13, the high throughput data18 is transmitted over the four conductive wires (11 a-11 d) of thecable 11 and the control data 17 is multiplexed with the high-throughputdata 18. Alternatively (not shown in the drawings) the high throughputdata 18 and the multiplexed controls 17 are transmitted over a firstsubset of the conductive wires of the cable 11, and the controls 16 ofthe LPPF mode of operation 14 are transmitted over a subset of the firstsubset. Optionally, the cable 11 may be one of the following cables:CAT5, CAT5e, CAT6, CAT6a, CAT7, or coax.

In one embodiment, the MDTCL has two or more LPPF modes of operation,featuring different power consumptions, transfer of different datatypes, and/or different available functionalities. A few examples ofLPPF functionalities include: transferring Ethernet without video,transferring the system controls, transferring audio, or a combinationthereof. According to another example, the LPPF mode of operation maytransfer one or more of the following data types: standby control data,multimedia control data, auto-negotiation data, topology discovery data,network addressing data, general data, or consumer electronic control(CEC) data. Examples of electronic devices which may take advantage ofsuch an LPPF mode of operation include one or more of the following: adisplay (such as a television, projector, or plasma display), amultimedia source, an audio system, a receiver, a tuner, an amplifier,or an HDMI compatible device.

FIG. 5A illustrates one embodiment of a MDTCL having one active mode ofoperation and two LPPF modes of operation. The different modes ofoperations are implemented using multi function transceivers denoted inFIG. 5A by small squares. The multi function transceivers have active,#1LPPF, and #2LPPF modes of operations. As illustrated, the DVD 59transmits uncompressed content to the TV 62. Therefore, MDTCLs 60 and 61are in the active mode of operation, i.e. the transceivers are in theiractive mode. The communication is transmitted through the Digital LivingNetwork Alliance (DLNA) compliant audio video (AV) receiver with DLNAclient capabilities 56. The PC DLNA server 51 transmits to the TV 62 CECcommunications and a compressed video stream using DLNA over Ethernet.Therefore, MDTCLs 52 and 55 operate in the #2LPPF mode of operationwhich supports the required functionalities, e.g. CEC transactions andcompressed video over Ethernet. The transceivers implementing the #2LPPFmode of operation consume less power than the power consumed whenoperating in the active mode of operation. As illustrated, PC 51 isconnected to TV 62 in a daisy chain through TV 54. TV 54 may be instandby mode. In order to save power while supporting the various MDTCLmodes of operation, TV 54 may have a plurality of standby modescorresponding to the MDTCL modes of operation. In one embodiment, thestandby mode of operation is determined by the MDTCL mode of operation.The STB 57 is in standby mode. Therefore, MDTCL 58 operates in the#1LPPF mode of operation, which supports only CEC transactions. The TV62 receives uncompressed video from DVD 59 and compressed video from PC51 and, as an example, may use the two streams for displaying picture inpicture.

In one embodiment, the LPPF modes of operation and their correspondingstandby modes are determined according to one or more of the following:(i) the amount of the transmitted bandwidth, (ii) the type oftransmitted data, or (iii) the required functionality of the MDTCL.Examples of three LPPF modes of operation include the following: (i) anLPPF mode for transmitting video system control data, (ii) an LPPF modefor transmitting video system control data and audio data, and (iii) anLPPF mode for transmitting video system control data and general data,such as Ethernet data. The third example may also be considered as a lowpower mode because the Ethernet transmission consumes less power thanuncompressed video transmission. In one embodiment, 100 Mb Ethernet istransmitted over two pairs of wires of a CATx cable, and video systemcontrol data is transmitted over the other two pairs of wires of theCATx cable.

The communication link in one or more of the embodiments discussedherein may be a multi stream communication link. Alternatively oradditionally, the communication link in one or more of the embodimentsdiscussed herein may be a symmetric communication link. Stillalternatively or additionally, the communication link in one or more ofthe embodiments discussed herein may be a symmetric and multi streamcommunication link. FIG. 5B illustrates one embodiment of a multi-streamdaisy chain comprising two source devices (5B1 and 5B2) and two displaydevices (5B3 and 5B4). Source device 5B1 and display device 5B4 are in astandby mode of operation; therefore, MDTCLs 5B5 and 5B7 are in theirLPPF mode of operation. Source device 5B2 transmits to display device5B3; therefore, the multi stream MDTCL 5B6 is in its active mode. In oneexample, the multi stream MDTCL 5B6 transfers, in its active mode ofoperation, video from source device 5B2 to display device 5B3 and systemcontrols between source device 5B2 and display device 5B3, and systemcontrols between source device 5B1 and display device 5B4. It is to beunderstood that the MDTCLs 5B5 and 5B7 may also be multi stream MDTCLs.

In one embodiment, a daisy chain device includes a daisy chain mechanismwhich manages and supports the communication link. In one embodiment,the daisy chain mechanism may operate almost independently of the daisychain device. For example, the daisy chain mechanism may operate in itsactive mode of operation while the daisy chain device is in a standbymode of operation. In one embodiment, the daisy chain mechanismcomprises a first and a second MDTCL transceiver that may operate indifferent modes of operation. Referring again to FIG. 5B as an example,the first MDTCL transceiver of source device 5B2 may communicate withsource device 5B1 in the LPPF mode of operation, while the second MDTCLtransceiver may communicate with display device 5B3 in the active modeof operation. All other combinations, such as Active-LPPF, LPPF-LPPF andactive-active may be possible.

FIG. 2A illustrates one embodiment of a state machine for operating aMDTCL over the same physical media (e.g. a copper cable). In thisembodiment, the communication link has an Ethernet mode of operation 24and two MDTCL modes of operation, named LPPF mode of operation 26 andactive mode of operation 28. Optionally, during the Link PartnerDetection mode of operation 22, each side connected to the link performsauto negotiation with the other side, if exists. The Link PartnerDetection mode of operation 22 may be entered upon waking up, turningon, or resetting. In one embodiment, one or more interfaces are tested.For example, an Ethernet interface may be tested 22 a; if the Ethernetinterface is established, the state of the communication link changes toEthernet mode of operation 24; otherwise, a MDTCL application, such asHDMI, may be tested 22 b; if both sides support the MDTCL properties,the state of the communication link changes to LPPF mode of operation26. Optionally, if the link is plugged out (28 c, 28 d) or there is aninvalid link response 26 a, the MDTCL switches back to the link partnerdetection mode 22.

Referring to FIG. 1B and FIG. 2A, optionally, upon entering the LPPFmode of operation 26, the communication link receives from both sides(19 a, 19 b) information about their modes of operation. If both sides(19 a and 19 b) are in active modes of operation, the communication linkswitches to its active mode of operation 28. If at least one of thesides (19 a or 19 b) is in standby mode, the communication link stays inthe LPPF mode of operation 26.

While operating in the active mode of operation 28, if the link is down28 b or one of the sides (19 a, 19 b) changes its mode to #1LPPF or#2LPPF (28 a, 28 e), the communication link enters the LPPF mode ofoperation 26. Optionally, during the active mode of operation 28, one ofthe following combinations of data types may be transmitted over thecommunication link: uncompressed high definition digital video data andbidirectional control data, uncompressed high definition digital videoand audio data and bidirectional control data, uncompressed highdefinition digital video and audio data and bidirectional control dataand Ethernet general data.

Optionally, during the LPPF mode of operation 26, the communication linkis able to transmit control signals needed for the system to determinewhether it should change its mode of operation, and/or perform otherstandby mode activities, such as the standby mode activities defined byDVI™ (Digital Visual Interface), HDMI™, DisplayPort™, or DIVA™standards. In one embodiment, the LPPF mode of operation 26 may supportone or more of the following control signals: (i) control signals neededfor nodes in the network to go into and out of standby mode, (ii)control signals supporting network topology changes performed while thedevices are in standby mode, (iii) control signals for finding thenetwork topology while some of the network is in standby, or (iv)control signals for assigning identification numbers to the variousnodes in the network while the network is in standby mode. In oneembodiment, the LPPF mode of operation 26 supports the control signalsdefined by the HDMI standard. For example, the LPPF mode of operation 26may support one or more of the following HDMI control signals: EDID DDCtransactions, HPD, 5V status signals, or transparent transfer of CECtransactions.

FIG. 2B illustrates one embodiment of a state machine for operating aMDTCL over the same physical media. In this embodiment, the multifunction transceivers used by the MDTCL have an active mode of operation28 and two LPPF modes of operation (26 a, 26 b). In one example, eachmode of the multi function transceiver processes different data type(s)or different combination(s) of data types, such that the different modesof operation (26 a, 26 b, 28) feature different functionalities andoptionally different power consumptions.

During the link partner detection mode 22, the system sets thefunction(s) to be operated by the multi function transceiver. Forexample, if the devices connected to both sides of the MDTCL are intheir active mode of operation, the multi function transceivers are setto be (22 c) in the active mode of operation 28. If a first deviceconnected to the MDTCL is in the active mode, and a second deviceconnected to the MDTCL is in another mode, a communication takes placebetween the two devices, optionally resulting in the second devicechanging its mode to the active mode of operation 28, or the firstdevice changing its mode to another mode that is accepted by the seconddevice. The MDTCL may also switch between the various LPPF modes ofoperation (27 a, 27 b). For example, assuming a first and a seconddevice connected to the MDTCL are in the #1LPPF mode of operation 26 a,the first device may transmit a message to the second device that mayagree to switch mode, resulting in both devices switching 27 a to the#2LPPF mode of operation 26 b. Alternatively, assuming the first and thesecond device connected to the MDTCL are in the #2LPPF mode of operation26 b, the first device may notify the second device it switches to the#1LPPF mode of operation, resulting in both devices switching to the#1LPPF mode of operation.

FIG. 2C illustrates a configuration supporting the feature of switchingbetween the various LPPF modes of operation using messages. In theillustrated embodiment, the #1LPPF mode of operation 2C1 transmits overpairs of wires 11 c and 11 d. The #2 LPPF mode of operation 2C3, whichtransmits over the four pairs of wires (11 a-11 d), transmitsapproximately the same data over pairs of wires 11 c and 11 d as the#1LPPF mode of operation and transmits additional data over pairs ofwires 11 a and 11 b. Because the same data transmissions over the samepairs of wires are used by the #1 and the #2 modes of operations, it ispossible to switch between the #1 and the #2 modes of operations usingmessages transmitted over pairs of wires 11 c and 11 d.

FIG. 19 is a flow diagram illustrating one method for operating a multidata type communication link transceiver, comprising the followingsteps: In step 190, testing the type of the link partner transceiver. Ifthe link partner transceiver is not a multi data type communication linktransceiver, operating the multi data type communication link accordingto the detected type of the link partner transceiver (step 192). If thelink partner transceiver is a multi data type communication linktransceiver, further comprising the steps of negotiating thefunctionality required from the multi data type communication link withthe link partner (step 194), and switching to an appropriate mode ofoperation (step 196).

FIG. 20 is a flow diagram illustrating one method for operating a multidata type communication link transceiver, comprising the followingsteps: In step 200, negotiating with a link partner the functionalityrequired from the multi data type communication link transceiver. And instep 202, switching to an appropriate mode of operation, which supportsthe required functionality, selected from the group of at least a firstactive mode of operation and a second LPPF mode of operation; whereinthe required functionality is based on the data types to be transmittedover the multi data type communication link, and the second LPPF mode ofoperation transmits over a subset of the physical media used by thefirst active mode of operation.

Various auto negotiations may be implemented for different devicesrunning different interfaces. The various auto negotiation protocols maydiffer in the following non-limiting features: (i) using differentconductive wires for identification. For example, Ethernet uses the pairof conductive wires A and B, while a MDTCL may use the pair ofconductive wires C and D; (ii) using different transmission amplitudes.For example, a MDTCL may utilize amplitude which is below the lowerthreshold of Ethernet; or (iii) using different pulse shapes. Forexample, a MDTCL may use a pulse shape that is different from the pulseshape used by Ethernet.

U.S. patent application Ser. No. 11/703,080, filed on Feb. 7, 2007,which is incorporated herein by reference in its entirety, disclosesmethods and systems, which may be used with the discussed embodiments,for transmitting the following data types over the same wires: (i)uncompressed high definition digital video data, (ii) uncompressed audiodata, (iii) bidirectional control data, and/or (iv) general data, suchas Ethernet.

Power Saving Techniques

Since the bandwidth of the LPPF mode of operation is significantly lowerthan the bandwidth of the active mode of operation, the LPPF mode ofoperation may utilize one or more of the following techniques for powerreduction.

The LPPF mode of operation may utilize a simpler modulation scheme thanthe modulation scheme used in the active mode of operation 28. FIG. 16is a flow diagram illustrating one method comprising the followingsteps: in step 160, transmitting in a first mode of operation a firstdata stream, comprising at least two data types, over conductive wiresusing a first modulation scheme. And in step 162, transmitting in asecond LPPF mode of operation a second data stream, comprising less datatypes than the first data stream, over at least a subset of theconductive wires used for transmitting the first data stream, using asecond modulation scheme that is simpler than the first modulationscheme.

The LPPF mode of operation may utilize a much lower symbol rate than thesymbol rate used in the active mode of operation 28. FIG. 17 is a flowdiagram illustrating one method comprising the following steps: in step170, transmitting in a first mode of operation bidirectional databetween a source device and a sink device and unidirectionaluncompressed high definition digital video from the source device to thesink device over at least a first subset of conductive wires comprisedin a cable. And in step 172, transmitting in a second LPPF mode ofoperation bidirectional data between the source device and the sinkdevice over at least a second subset of the conductive wires used by thefirst mode of operation for transmitting the unidirectional uncompressedhigh definition digital video. Wherein, the bidirectional datatransmitted in the second LPPF mode of operation comprises at least onedata type that is also transmitted in the bidirectional data of thefirst mode of operation, and the transmissions in the second LPPF modeof operation are have a much lower symbol rate compared to thetransmissions in the first mode of operation.

The transmissions in the LPPF mode of operation may utilize a subset ofthe wires used for the active mode of operation 28. For example, whenoperating over a multi twisted pairs cable, such as CAT5e, one pair maybe used for transmitting and one pair for receiving.

Instead of transmitting full duplex over the same wires, in the LPPFmode of operation, a unidirectional transmission may be transmitted overa first set of wires and a unidirectional transmission may betransmitted to the opposite side over a second set of wires, where thefirst and second sets of wires are also used by the active mode ofoperation. Utilizing unidirectional transmissions in the LPPF mode ofoperation reduces the receiver's signal analysis workload and as aresult reduces the receiver's power consumption.

low amplitude transmissions may be used in the LPPF mode of operation.

In the LPPF mode of operation, the link may be activated only when validdata is available for transmissions, instead of activating the link alsowhen there is no data to transmit, usually using idle symbols.

In the LPPF mode of operation, the link may be activated on request andmay be maintained only when additional transmissions are expected soon.Synchronization and timing problems as a result of turning off the linkmay be resolved by a self clocking code, such as Manchester II, whereinthe clock is embedded within the data.

In the LPPF mode of operation, signal acquisition may be performed eachtime a transaction is to be performed.

In the LPPF mode of operation, a modem having at least two modes ofoperation may be utilized as further discussed below. The plural modesmodem may be implemented as one or more modems connected to the samemedia through the same analog front ends or through different analogfront ends. In one embodiment, the first mode of operation is a 10 GbpsEthernet modem and the second mode of operation is a low power modemutilizing one or more of the above described techniques (lowerfrequency, fewer conductive wires, low amplitude, partial functionality,maintaining the link, Synchronization, signal acquisition, lower symbolrate, or modem with two modes of operation).

FIG. 18 is a flow diagram illustrating one method comprising thefollowing steps: in step 180, transmitting in a first mode of operation,over a cable comprising conductive wires, a first asymmetric data streamcomprising at least two data types. And in step 182, transmitting in asecond LPPF mode of operation, over a subset of the conductive wiresused by the first mode of operation, a second bidirectional data streamhaving a much lower throughput (e.g. at most approximately 1/10 of thethroughput) and comprising less data types than the first asymmetricdata stream.

MDTCL Modems

FIG. 6 illustrates one example of a receiving path of a receiver used ina MDTCL. The illustrated receiver has (i) an active mode of operation,in which it receives a video stream 66 a, an audio stream 66 b, and acontrol stream 66 c; and (ii) an LPPF mode of operation, in which itreceives only the control stream 66 c. While the receiver is in itsactive mode of operation, the video stream 66 a, the audio stream 66 b,and the control stream 66 c are received from the communication mediumthrough the active mode of operation version of the receiver's analogfront end 69 a, the active mode of operation version of the DSP receiver69 b, and the active mode of operation version of the link layer datademultiplexer 63. The optional selector 65 selects the control streamfrom the active path. In another embodiment, the selector 65 is notrequired because the control stream received in the active mode ofoperation is forwarded to a first destination and the control streamreceived in the LPPF mode of operation is forwarded to a seconddestination. While the receiver is in its LPPF mode of operation, thecontrol stream 66 c is received from the communication medium throughthe LPPF mode of operation version of the receiver's analog front end 69a, the LPPF mode of operation version of the DSP receiver 69 c, and theLPPF mode of operation version of the link layer data demultiplexer 64.As illustrated by FIG. 6, in one embodiment, at least some part of thereceiver's analog front end is shared between the active receiving pathand the LPPF receiving path because the different data types arereceived from the same wires. The optional system controller 67 sets themode of operation of the selector 65 and the receiver's analog front end69 a according to the system controls received from the link layer datademultiplexer 63 the link layer LPPF data demultiplexer 64.

FIG. 7 illustrates one example of a transmitting path of a transmitterused in a MDTCL. The illustrated transmitter has (i) an active mode ofoperation, in which it transmits a video stream 70, an audio stream 71,and a control stream 72; and (ii) an LPPF mode of operation, in which ittransmits only the control stream 72. While the transmitter is in itsactive mode of operation, the video stream 70, audio stream 71, andcontrol stream 72 are transmitted to the communication medium throughthe active mode of operation version of the link layer data multiplexer73, the active mode of operation version of the transmit modulator 75,and the active mode of operation version of the transmitter's analogfront end 103 a. The optional selector 77 selects the video stream 70,audio stream 71, and control stream 72 from the active path. In anotherembodiment, the selector 77 is not required because the streams of theactive mode of operation are forwarded to a first analog front end andthe control stream of the LPPF mode of operation is forwarded to asecond analog front end. While the transmitter is in its LPPF mode ofoperation, the control stream 72 is transmitted to the communicationmedium through the LPPF mode of operation version of the link layer LPPFdata multiplexer 74, the LPPF mode of operation version of the transmitmodulator 76, and the LPPF mode of operation version of thetransmitter's analog front end 78. As illustrated by FIG. 7, in oneembodiment, at least some part of the transmitter's analog front end isshared between the active transmitting path and the LPPF transmittingpath because the different data types are transmitted over the samewires. The optional system controller 79 sets the mode of operation ofthe selector 77 and the transmitter's analog front end 78 using theillustrated “mode” signal, and provides the system controls to the linklayer data multiplexer 73 and to the link layer LPPF data multiplexer74.

MDTCL Transceivers

FIG. 8 illustrates an optional configuration, including a sourcetransceiver 81 and a sink transceiver 82, which is explained in detailby FIGS. 9 and 10. In the illustrated example, source transceiver 81transmits to sink transceiver 82 video data and audio data; andbidirectional control data is transmitted between the source transceiver81 and the sink transceiver 82. The video, audio and control data may betransmitted over the same wires.

FIG. 9 illustrates one embodiment of the sink side of a MDTCL, whereinthe sink is a television, which receives a video stream 90 a, an audiostream 90 b, and a bidirectional control stream 90 c. While the TV is inits active mode of operation, the optional system controller 91 a setsselectors 91 b and 91 c to pass the active path and sets the analogfront ends of the transmitted and the receiver (93 a, 93 b) to operatein their active mode of operation, according to the system controlsreceived from the link layer data demultiplexer 98 a. The systemcontroller 91 a also provides the system controls to the link layer datamultiplexer 94 a. The TV transmits the control stream 90 c to thebidirectional communication medium through the active mode of operationversion of the link layer data multiplexer 94 a, the active mode ofoperation version of the transmit modulator 95 a, the active mode ofoperation version of the transmitter's analog front end 93 a, and thehybrid circuit 92. The TV receives the video stream 90 a, the audiostream 90 b, and the control stream 90 c from the bidirectionalcommunication medium through the hybrid circuit 92, the active mode ofoperation version of the receiver's analog front end 93 b, the activemode of operation version of the DSP receiver 97 a, and the active modeof operation version of the link layer data demultiplexer 98 a.

While the TV is in its LPPF mode of operation, the optional systemcontroller 91 a sets selectors 91 b and 91 c to pass the LPPF path andsets the analog front ends of the transmitter and the receiver (93 a, 93b) to operate in their LPPF mode of operation according to the systemcontrols received from the link layer LPPF data demultiplexer 98 b. Thesystem controller 91 a also provides the system controls to the linklayer LPPF data multiplexer 94 b. The TV transmits the a control stream90 c to the bidirectional communication medium through the LPPF mode ofoperation version of the link layer data multiplexer 94 b, the LPPF modeof operation version of the transmit modulator 95 b, the LPPF mode ofoperation version of the transmitter's analog front end 93 a, and thehybrid circuit 92. The TV receives a control stream 90 c from thebidirectional communication medium through the hybrid circuit 92, theLPPF mode of operation version of the receiver's analog front end 93 b,the LPPF mode of operation version of the DSP receiver 97 b, and theLPPF mode of operation version of the link layer data demultiplexer 98b.

FIG. 10 illustrates one embodiment of the source side of a MDTCL,wherein the source may be an STB, DVD, Blu-Ray, game console, PC, or anyother device that transmits a video stream 100 a, an audio stream 100 b,and a bidirectional control stream 100 c. While the source device is inits active mode of operation, the optional system controller 101 setsselectors 102 a and 102 b to pass the active path and sets the analogfront ends of the transmitter and the receiver (103 a, 103 b) to operatein their active mode of operation according to the system controlsreceived from the link layer data demultiplexer 108 a. The systemcontroller 101 also provides the system controls to the link layer datamultiplexer 104 a. The source device transmits a video stream 100 a, anaudio stream 100 b, and a control stream 100 c to the bidirectionalcommunication medium through the active mode of operation version of thelink layer LPPF data multiplexer 104 a, the active mode of operationversion of the transmit modulator 105 a, the active mode of operationversion of the transmitter's analog front end 103 a, and the hybridcircuit 106. The source device receives a control stream 100 c from thebidirectional communication medium through the hybrid circuit 106, theactive mode of operation version of the receiver's analog front end 103b, the active mode of operation version of the DSP receiver 107 a, andthe active mode of operation version of the link layer datademultiplexer 108 a.

While the source device is in its LPPF mode of operation, the systemcontroller 101 sets selectors 102 a and 102 b to pass the LPPF path andsets the analog front ends of the transmitter and the receiver (103 a,103 b) to operate in their LPPF mode of operation according to thesystem controls received from the link layer LPPF data demultiplexer 108b. The system controller 101 also provides the system controls to thelink layer LPPF data multiplexer 104 b. The source device transmits acontrol stream 100 c to the bidirectional communication medium throughthe LPPF mode of operation version of the link layer data multiplexer104 b, the LPPF mode of operation version of the transmit modulator 105b, the LPPF mode of operation version of the transmitter's analog frontend 103 a, and the hybrid circuit 106. The source device receives acontrol stream 100 c from the bidirectional communication medium throughthe hybrid circuit 106, the LPPF mode of operation version of thereceiver's analog front end 103 b, the LPPF mode of operation version ofthe DSP receiver 107 b, and the LPPF mode of operation version of thelink layer data demultiplexer 108 b.

Ethernet Low Power Partial Functionality Operation Mode

In one embodiment, a modified Ethernet interface includes an LPPF modeof operation that transmits only a predefined set of data types.Ethernet with LPPF mode is especially useful when operating withconsumer electronic devices, such as, but not limited to, displaydevices, or source devices such as STBs, DVD players, Video players,Blu-Ray players, game consoles, or multimedia servers.

In one example, a consumer electronic source device may use Ethernet fortransferring, in its active mode of operation, video, audio, and controldata to a display device. While the consumer electronic source devicedoes not transmit video and audio data, for example, when it is instandby mode, the consumer electronic source device may still need totransmit some system controls and/or audio data, which consume much lessbandwidth than consumed in the active mode of operation.

FIG. 13 illustrates one embodiment of a communication device, alsoreferred to as a modified Ethernet interface, having two types of PHYDSPs. The first PHY DSP is a standard Ethernet PHY DSP 133, and thesecond PHY DSP is an LPPF PHY DSP 134. The LPPF mode of operation mayutilize one or more of the power reduction techniques described herein.

The data link layer (MAC) 131 of the modified Ethernet interface mayoperate the standard Ethernet PHY DSP 133 or the LPPF PHY DSP 134. Theoptional system controller 130 a sets selectors 132 and 135 to pass thesignals of the required mode of operation. Optionally, the analog frontend 136 has also two modes of operation, corresponding to the two PHYmodes of operation. In one embodiment, the MAC 131 determines which PHYto operate. In another embodiment, the application layer 130 determineswhich PHY to operate using the following steps:

The MAC 131 on a first side of the communication link receives from theapplication layer 130 an indication about the required mode of operationof the communication link, for example, active, #1LPPF, or #2LPPF modesof operation.

The MAC 131 communicates with the device on the other side of thecommunication link in order to coordinate the operation of thecommunication link. For example, the first device (connected to thefirst side of the communication link) may request from the second device(connected to the second side of the communication link) to switch from#1LPPF mode to active mode; if the second device accepts the request,the communication link switches to active mode; if the second devicedoes not accept the request, the communication link may stay in itscurrent mode of operation, or switch to a predefined mode of operationsuch as the default mode of operation, or reset the link. In oneembodiment, when one device connected to the communication link switchesfrom the active mode to one of the LPPF modes, or from a comprehensiveLPPF mode to slimmer LPPF mode, the device on the other side must alsochange its mode of operation.

In one embodiment, the application layer 130 determines which of theavailable physical layers to operate and which data types are to betransmitted over the communication link. In this case, only framesassociated with the allowable data types are forwarded to the MAC 131;frames associated with other data types are not forwarded to the MAC131. In one embodiment, the application layer 130 determines the typeassociated with each frame by communicating with the data sources. Forexample, a video source may be able to identify the data types of theframes it supplies, such as video data, audio data, and AV controls, andto forward that information to the application layer 130. In oneembodiment, the application layer 130 determines the type associatedwith each frame according to the source of each frame. For example: anEthernet port supplies a general data type; an HDMI port supplies avideo data stream, an audio data stream and control streams; and anaudio system provides an audio data stream.

In another embodiment, the application layer 130 sets the communicationlink's mode of operation and notifies the MAC 131 about the data typeassociated with each frame it receives. According to the selected modeof operation and the data type associated with each frame, the MAC 131determines which frame will be transmitted over the communication linkand selects the PHY that will be used for modulating the signals. Forexample, and with reference to FIG. 14, a DLNA server 140 is able totransmit high definition video and compressed video over Ethernet. Inthe active mode of operation, the MAC layer 141 transmits all the typesof data it receives from the DLNA server 140 through 10 Gbps EthernetPHY DSP 143. In the #1LPPF mode of operation, the MAC layer 141transmits only audio data and system control data it receives from theDLNA server 140 through #1LPPF PHY DSP 144. In the #2LPPF mode ofoperation, the MAC layer 141 transmits only system control data itreceives from the DLNA server 140 through #2LPPF PHY DSP 144. The powerconsumption of the 10 Gbps Ethernet PHY DSP 143 is significantly higherthan the power consumption of the #1LPPF PHY DSP 144 which issignificantly higher than the power consumption of the #2LPPF PHY DSP145.

It is to be understood that FIGS. 13 and 14 may be amended to includedesignated data link layers for each mode of operation, similar to thestructures illustrated in FIGS. 9 and 10. FIG. 15 illustrates avariation of FIG. 13 including separate MACs for the Ethernet path andthe LPPF path. The Ethernet MAC 154 and the LPPF MAC 156 communicatewith application layer 130 through selector 152 that is optionallyoperated by system controller 150.

In one embodiment, the LPPF mode does not change the structure of theEthernet frame. Maintaining the frame structure enables smoothtransitions between network hops. In one embodiment, the LPPF mode andthe active mode utilize different frame structures. Utilizing differentframe structures may improve the efficiency and reduce overheads.

Diva Low Power Partial Functionality Operation Mode

It is to be understood that although the name “DIVA” is used herein, theclaimed invention should not be limited, in any way, to the DigitalInterface for Video and Audio (DIVA) initiated by a working group ofsome leading Chinese consumer electronics companies, described inhttp://www.diva-interface.org

FIG. 11 illustrates one embodiment of a multimedia system including fourpairs of wires. Uncompressed video data and uncompressed audio data,optionally multiplexed with video control data, are transmitted by threetransmitters (111 a, 112 a, 113 a), over three links (111 b, 112 b, 113b), to three receivers (111 c, 112 c, 113 c). Transceivers 114 a and 114c form a bidirectional MDTCL 114 b. In one embodiment, approximately 4.5Gbps of video and audio are transmitted over three links (111 b, 112 b,113 b), and 4.5 Gbps of data is transmitted, half-duplex, over thefourth link 114 b. Optionally, each of the four communication links (111b, 112 b, 113 b, and 114 b) is made of a pair of copper wires.Optionally, the transmissions are SerDes (Serializer/Deserializer).

FIG. 12 illustrates one embodiment of the state machine of MDTCL 114 bof FIG. 11 adapted to DIVA. The MDTCL 114 b may transfer, in its activemode of operation 128, the following data types over a pair of wires:bidirectional system control data, bidirectional general data, andoptional unidirectional audio data from transceiver 114 c to transceiver114 a. Optionally, the general data includes Ethernet Data. The MDTCL114 b may feature one or more of the following LPPF modes of operation:(i) a first optional LPPF mode of operation 124 for transferringbidirectional system controls; (ii) a second optional LPPF mode ofoperation 126 for transferring bidirectional system controls andunidirectional audio from transceiver 114 c to transceiver 114 a; or(iii) a third optional LPPF mode of operation (not illustrated in thefigure) for transferring bidirectional system controls and bidirectionalgeneral data in a rate that is lower than the transfer rate of thebidirectional data utilized by the active mode of operation. Forexample, in its active mode of operation, the system may transmit halfduplex general data in a rate of 4.5 Gbps, while in its third LPPF modeof operation, the system may transmit half duplex general data in a rateof 1 Gbps, 100 Mbps, 10 Mbps, or 1 Mbps.

The LPPF mode of operation may utilize one or more of the powerreduction techniques described herein. For example, operating the MDTCL114 b using different rates, using a smaller amplitude, and/ortransmitting over the link only when there is a need to transmit data.

Although the embodiments have been described in considerable detail withreference to certain embodiments thereof, other embodiments arepossible.

Certain features of the embodiments, which may, for clarity, bedescribed in the context of separate embodiments, may also be providedin various combinations in a single embodiment. Conversely, variousfeatures of the embodiments, which may, for brevity, be described in thecontext of a single embodiment, may also be provided separately or inany suitable sub-combination.

The embodiments are not limited in their applications to the details ofthe order or sequence of steps of operation of methods, or to details ofimplementation of devices, set in the description, drawings, orexamples.

While the methods disclosed herein have been described and shown withreference to particular steps performed in a particular order, it willbe understood that these steps may be combined, sub-divided, orreordered to form an equivalent method without departing from theteachings of the embodiments. Accordingly, unless specifically indicatedherein, the order and grouping of the steps is not a limitation of theembodiments.

Any citation or identification of any reference in this applicationshall not be construed as an admission that such reference is availableas prior art to the embodiments of the present invention.

While the embodiments have been described in conjunction with specificexamples thereof, it is to be understood that they have been presentedby way of example, and not limitation. Moreover, it is evident that manyalternatives, modifications and variations will be apparent to thoseskilled in the art. Accordingly, it is intended to embrace all suchalternatives, modifications and variations that fall within the spiritand scope of the appended claims and their equivalents. In the claims,means-plus-function clauses are intended to cover the structuresdescribed herein as performing the recited function and not onlystructural equivalents, but also equivalent structures.

1. A communication link comprising: a cable containing four pairs ofwires, three transmitters, three receivers, and two transceivers; thethree transmitters operative to transmit uncompressed video data anddata over three of the pairs of wires to the three receivers; the twotransceivers operative to form a bidirectional multi data typecommunication link over the fourth pair of the pairs of wires; an activemode of operation for transmitting the uncompressed video data over thethree pairs of wires from the three transmitters to the three receivers,and for transmitting bidirectional system control data, bidirectionalgeneral data, and audio data over the fourth pair of wires between thetwo transceivers; and a low-power partial-functionality (LPPF) mode ofoperation for transmitting over the fourth pair of wires a subset of thedata types transmitted in the active mode of operation over the fourthpair of wires.
 2. The communication link of claim 1, wherein in the LPPFmode of operation bidirectional system control data are transmitted overthe fourth pair of wires.
 3. The communication link of claim 2, whereinthe uncompressed video data is multiplexed with video control data, andthe communication over the fourth pair of wires is half-duplex.
 4. Thecommunication link of claim 2, wherein the uncompressed video data ismultiplexed with video control data, each of the three transmitterstransmits approximately 4.5 Gbps of video and audio, and thecommunication over the fourth pair of wires is half-duplex.
 5. Thecommunication link of claim 1, wherein the three transmitters arefurther operative to transmit audio data.
 6. The communication link ofclaim 1, wherein in the LPPF mode of operation bidirectional systemcontrol data and unidirectional audio are transmitted over the fourthpair of wires.
 7. The communication link of claim 1, wherein in the LPPFmode of operation bidirectional system control data and bidirectionalgeneral data are transmitted over the fourth pair of the wires in alower rate than the transfer rate of the bidirectional data in theactive mode of operation.
 8. The communication link of claim 7, whereinin the active mode of operation, the communication link over the fourthpair of wires transmits half duplex general data in a rate of betweenabout 2 Gbps and 8 Gbps, while in the LPPF mode of operation, thecommunication link transmits half duplex general data in a rate of about1 Gbps, 100 Mbps, 10 Mbps, or 1 Mbps.
 9. The communication link of claim1, wherein one or more of the following power reduction techniques isutilized in the LPPF mode of operation: using different rates, usinglower amplitude, transmitting over the link only when there is a need totransmit data, or utilizing simpler modulation.
 10. The communicationlink of claim 1, wherein the general data comprises Ethernet Data. 11.The communication link of claim 1, wherein the wires are made of copperand the transmissions are two level pulse amplitude modulation.
 12. Thecommunication link of claim 1, wherein the wires are made of copper andthe transmissions utilize 8B/10B encoding.
 13. The communication link ofclaim 1, wherein the LPPF mode of operation transmits in one directionover one of the first three pairs of wires and in the other directionover the fourth pair of wires.
 14. The communication link of claim 13,wherein the transmitter transmitting over the one of the first threepairs of wires utilizes a lower rate in the LPPF mode of operation thanin the active mode of operation.
 15. The communication link of claim 13,wherein the transmitter transmitting over the one of the first threepairs of wires utilizes a simpler modulation in the LPPF mode ofoperation than in the active mode of operation.
 16. A communication linkcomprising: a cable containing four pairs of wires, three transmitters,three receivers, and two transceivers; the three transmitters operativeto transmit uncompressed video data and audio data over three of thepairs of wires to the three receivers; the two transceivers operative toform a bidirectional multi data type communication link over the fourthpair of the pair of wires; an active mode of operation for transmittingthe uncompressed video data and the audio data over the three pairs ofwires from the three transmitters to the three receivers, and fortransmitting bidirectional data over the fourth pair of wires betweenthe two transceivers; and a first low-power partial-functionality (LPPF)mode of operation for transmitting bidirectional system control data.17. The communication link of claim 16, wherein the first LPPF mode ofoperation transmits over the fourth pair of wires.
 18. The communicationlink of claim 16, wherein the first LPPF mode of operation transmits inone direction over one of the first three pairs of wires and in theother direction over the fourth pair of wires.
 19. The communicationlink of claim 16, further comprising a second LPPF mode of operation fortransmitting bidirectional system control data and unidirectional audio.20. The communication link of claim 19, further comprising a third LPPFmode of operation for transmitting bidirectional system control data andbidirectional general data in a lower rate than the transfer rate of thebidirectional data in the active mode of operation.
 21. Thecommunication link of claim 20, wherein the LPPF modes of operationtransmit over the fourth pair of wires.
 22. The communication link ofclaim 20, wherein the LPPF modes of operation transmit in one directionover one of the first three pairs of wires and in the other directionover the fourth pair of wires.
 23. The communication link of claim 22,wherein the transmitter transmitting over the one of the first threepairs of wires utilizes a lower rate in the LPPF mode of operation thanin the active mode of operation.
 24. The communication link of claim 22,wherein the transmitter transmitting over the one of the first threepairs of wires utilizes a simpler modulation in the LPPF mode ofoperation than in the active mode of operation.
 25. The communicationlink of claim 20, wherein in the active mode of operation, thecommunication link over the fourth pair of wires transmits half duplexgeneral data in a rate of between about 2 Gbps and 8 Gbps, while in thethird LPPF mode of operation, the communication link transmits halfduplex general data in a rate of about 1 Gbps, 100 Mbps, 10 Mbps, or 1Mbps.
 26. The communication link of claim 16, wherein the bidirectionaldata transmitted in the active mode of operation comprises one or moreof the following: bidirectional system control data, bidirectionalgeneral data, and audio data.
 27. The communication link of claim 16,wherein the general data includes Ethernet Data.
 28. The communicationlink of claim 16, wherein one or more of the following power reductiontechniques is utilized in the first LPPF mode of operation: usingdifferent rates, using lower amplitude, transmitting over the link onlywhen there is a need to transmit data, or utilizing simpler modulation.29. The communication link of claim 16, wherein the wires are made ofcopper and the transmissions are two level pulse amplitude modulation.30. A communication device comprising: a cable containing wires, atleast one transmitter, and a transceiver; the at least one transmitteroperative to transmit uncompressed video data over a first subset of thewires, and the transceiver operative to transmit bidirectional datacomprising at least two data types over a second subset of the wires,wherein the first and the second subsets of the wires do not overlap; anactive mode of operation for transmitting by the transmitter theuncompressed video data over the first subset of the wires, and fortransmitting and receiving by the transceiver the bidirectional dataover the second subset of the wires; and a low-powerpartial-functionality (LPPF) mode of operation for transmitting over athird subset of the wires a subset of the data types transmitted in theactive mode of operation over the second subset of the wires.
 31. Thecommunication device of claim 30, wherein the bidirectional datatransmitted over the second subset of the wires in the active mode ofoperation comprises: bidirectional system control data, bidirectionalgeneral data, and audio data.
 32. The communication device of claim 30,wherein the second subset and the third subset of the wires overlap. 33.The communication device of claim 30, wherein the wires are made ofcopper and the transmissions utilize 8B/10B encoding.
 34. Thecommunication device of claim 30, wherein the LPPF mode of operationtransmits in one direction over one pair of the wires of the firstsubset and in the other direction over one pair of the wires of thesecond subset.
 35. The communication device of claim 34, wherein thetransmitter transmitting over the one pair of the wires of the firstsubset utilizes a lower rate in the LPPF mode of operation than in theactive mode of operation.
 36. The communication device of claim 34,wherein the transmitter transmitting over the one pair of the wires ofthe first subset utilizes a simpler modulation in the LPPF mode ofoperation than in the active mode of operation.
 37. The communicationdevice of claim 30, wherein the second subset of the wires comprises twopairs of wires and the LPPF mode of operation transmits in one directionover one pair of the wires of the second subset and in the otherdirection over the second pair of the wires of the second subset. 38.The communication device of claim 30, wherein the uncompressed videodata is multiplexed with video control data, and the communication overthe second subset of the wires is half-duplex.
 39. The communicationdevice of claim 30, wherein one or more of the following power reductiontechniques is utilized in the LPPF mode of operation: using differentrates, using lower amplitude, transmitting over the link only when thereis a need to transmit data, or utilizing simpler modulation.